I have a small room just off my basement that used to hold a pool pump and heater, which is now long gone. The room is approx 8x10 with a 5' ceiling. It is entirely underground and connects to the basement. I store wood in there. The joint between the ceiling of the wood room and the basement foundation has developed a leak resulting in water in the basement and wood room. I dug the dirt back and, on first inspection, looks relatively well sealed with some sort of black substance...probably mastic. What do y'all suggest to fix this leak? Would it be worthwhile to improve the drainage right above this joint with something other just plain old dirt? Nothing is obviously wrong to my untrained eye so I need some help. First thought is some of that informercial spray-sealer stuff...but that might be a waste of time.
Upon second inspection, I found a few places where the black sealant has given way to the ceiling of my wood room. I'm in the process of chiseling all the old junk away and was pleased to find no more than a hairline crack at the joint to the foundation of the house. Since the crack is so small, all I really need is a thin seal-coat. Would silicon be OK?
I would continue what you're doing, chisel it out, clean it with air from the compressor and caulk the chit out of it. You could do some low pressure injection system for a more permanent repair, but I think you will be fine if you clean it properly and caulk it.
I've got most of the big stuff chiseled out. Going to wait on it to dry and knock the rest of the dirt of with a wire wheel, blow with compressed air, and repeat until I have good clean surface. Then I'll ________? the chit out of it and hope for the best. I'm not going to re-bury it until I know it isn't leaking anymore.
How big is the crack...When you say big stuff, It may be to large to caulk without a backer rod or something similar?
The crack is pretty much hairline. Can get a fingernail in it but that's about it. The big stuff is the old black sealant...they put a pretty good bead on it originally.
Oh so the black stuff doesnt cover the whole roof? Its just on the crack? The whole underground area should be water proofed.
Seal it with an elastic mastic compatible with the existing materials, such as a rubberized tar type allows for movement without pulling away or recracking.
I decided to just expose the entire roof...cleaned it up real good...and sealed it all with rubberized foundation stuff. Going to let it dry...put down some plastic...and backfill.
I was going to suggest that approach, then changed my mind. With the plastic might want to lap the up the adjoining wall as it sounds like the ceiling is lower than the rest.
What leak? I don't see any leak.. Seriously though.. This stuff is great, but doesn't sound appropriate for your application.. And it's expensive too.
I decided last minute to just bite the bullet and do it right and not have to worry about it again. The hard part was that a low deck covers about half of it so getting that area dug out was less than fun. I dug an extra couple inches down along the edges for plastic to overhang down and will go up to the brick and the house with plastic. There are a few deck supports I had to work around and that will make getting a continuous sheet of plastic down pretry much impossible.
Maybe some of that spray on rubber membrane waterproofing they use in the boat commercial would solve those problem areas. "Flex Shot" or something like that name wise. I just used some to seal up a roof vent that was leaking but it was the caulk not the spray as I needed it underneath the flashing. Vent got beat up by hail caused nails to pull loose put a couple beads of that under there and then screwed the vent back -stainless screws. Seems ok so far.
